A conventional trimmer is described in Patent Document 1 (JP 2004-066347 A). The trimmer comprises a single trim cutter reciprocated in a vertical direction between a non-cutting position and a cutting position, and a table for positioning the bound material placed thereon. In this conventional trimmer, an operator puts the bound material on the table and positions it, and then the trim cutter is moved from the non-cutting position to the cutting position so as to cut an edge portion of the bound material. The operator rotates and positions the bound material at each of top, bottom and front edge cutting positions, sequentially. The operator reciprocates the trim cutter at each of the positions so as to cut each of the top, bottom and front edge portions. Thus, each of the edge portions of the bound material is trimmed.
Another conventional trimmer described in Patent Document 2 (U.S. Pat. No. 7,493,840 B) is a three-side trimmer. The three-side trimmer comprises a single trim cutter reciprocated in a vertical direction between a non-cutting position and a cutting position, a table for positioning a bound material placed thereon, and a rotate mechanism for rotating the table. A feed mechanism supplies the bound material on the table, and the table with the bound material is rotated so as to position the bound material at each of top, bottom and front edge cutting positions by the rotate mechanism. Then, the trim cutter reciprocates at each of the positions to cut the top, bottom and front edge portions.
In the above described conventional trimmer, the trim cutter reciprocates only once so as to cut the edge portion of the bound material. In case of FIG. 7, the edge portion 1a of the bound material 1 to be cut is long. In this case, when the edge portion 1a of the bound material 1 is cut by the trim cutter 20 only once, there is a possibility that the edge portion 1a of the bound material 1 may be bent, or a cover 1f of the bound material 1 may be torn. In case of FIG. 8, each of pages of the bound material 1 is an uncut page (“signature”), which is half folded, and the folded line 1g of the uncut pages must be cut. In this case, when the edge portion 1a (the folded line 1g) of the bound material 1 is cut by the trim cutter 20 only once, the edge portion 1a of the bound material 1 is not trimmed neatly. The conventional trimmer cannot trim the edge portion 1a of the bound material 1 neatly.
Patent Document 1: JP 2004-066347 A
Patent Document 2: U.S. Pat. No. 7,493,840 B